Method of preparing ores for flotation



Patented HARRY H. HENDRICKSON, 0F ARAVAIPA,

ARIZONA, ASSIGNOR T0 lamina COMPANY, or ,rnonmx, anrzon'a, a conrona'rron or nnnaann;

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N0 Drawing.

The invention relates to an improved method of preparing low gradeores, more particularly lead ores, for flotation to largely increase the recovery of metallic values and thereby render the treatment of such low grade ores commercially practicable. To this end, the invention comprises treating theores with a sulphidizing agent in the presence of water maintained at a temperature materially above the mean or average summer temperature and, preferably, at approximately 160 degrees Fahrenheit.

As indicated, the invention is especially applicable to treatment of low grade ores and deposits containing lead in oxidized form, running on an average of about 100 lbs. of lead per ton or approximately 5%, together with small amounts of other metals, such as silver and gold. Although many attempts were made to recover the values in ores and deposits containing lead in the approximate proportions stated, including the usual chemical treatments and flotation methods foil-the recovery of lead and similar metals, none of the operations were successful in recovering the lead in sufiicient quantities to render the operations commercially profitable, and, as a matter effect, the various steps to recover the lead were conducted at an actual loss until the present invention was developed and perfected and which has resulted in a substantially uniform extraction of to of the lead values, when the present invention was associated with the regulation flotation process em ployed in concentrating low grade ores,

dump tailings and similar deposits.

, In'carrying out the instant invention, the ores or mineral bearing materials in comminuted form are agitated in a suitable mixing apparatus, such as a concrete mixer, a vertical mixer or a rod mill with proper proportions ofsulphidizing reagent, such, for example, as sodium sulphide, and water in suflicient quantity to form a pulp of a density from 3 to 1 to 1 to 1, and maintaining the temperature ofthe pulp during the sulphidizing-reaction at a relatively high temperature, -i. e. approximately 160 degrees Fahrenheit, the resultant pulp containing sulphidized values, more particularly lead, in conditionto respond to the usual flota- Application filed September 9, 1926. Serial No. 134,576.

tion methods of concentration to recovery of from 60to 65%. practical application of the method was, applied to the material from the dump of a low grade silver mine, a systematic sampling of the material of the dump indicating that it contained an average of 100 lbs. of lead (5% in the form of oxidized lead material), 3 oz. of silver and .045 oz. of gold, to the ton. Many attempts to recover the metallic values by flotation, preceded by the usual and customary sulphidizing operations, were made, but, in no instance, was the recovery sufiicient to avoid an actual loss, the quantity of lead recovered beinginsufiicient to pay for the labor and materials employed in the operation. When, however, the preliminary sulphidizing reaction was carried out, with the pulp maintained at a temperature of approximately 160 degrees Fahrenheit, a uniformly suocessful'commercial recovery was obtained. The material from the dump was deposited in the mixer-and 5 lbs. of sodium sulphide to the ton of crude ore, together with water in an amount ap roximately equal to that of the ore, and the resultant pulp, during the agitation necessary to produce the sulphidizing of the mineral values, was maintained at the temperature aforesaid, to wit, approximately 160 degrees Fahrenheit After the thorough agitation of the pulp and the sulphidizing of the mineral values had been effected, under the temperature conditions indicated, the pulp was discharged from the mixer and approximate- 1y 1 lb. of Wood creosote, lb. shale oil and lb. of potassium xanthate per ton were added together with water in an amount suflicienttov give a pulp density of 3 to 1.

ive a lead The pulp was then pumped, preferably by a Fahrenheit; lbs. creosote per ton, .8; lbs.

shale oil per ton, .6; lbs. potassium Xanthate,

.05; lbs. sodium sulphide, 6.00.

The results were as follows:

Per cent Pb. Heads 5 Tails I 3. 5 Concentratesne 33 '2. The same ore, treated with the same reagents in the same amounts and the same pulp density, to wit, water heated to a temperature of 160 degrees Fahrenheit during the sulphidizing operation, gave the following results:

Percent Pb. Heads 5 Tails 1.8 Concentrates d4 From the foregoing, itiis evident that the ordinary and usual suiphidizing operation.

and the subsequent flotation, will not recover enough of the lead to make the enterprise a profitable-one. The first of the two examplesstated above is not commercially profitable, but indicates an. actual financial loss, as the value of the lead recovered is tion, which is both practicable and profitable.

in other words, the maintenance of the pulp during the sulphidizing reaction at the relatively high temperature of 180 degrees Fahrenheit, as compared with the common practics of effecting sulphidization with pulp temperatures at approximately that of the atmosphere, marks the difference between practical failure and commerciai success in the preliminary treatment and preparation of low grade ores or metal bearing material of the character indicated.

While the heating of the wateror pulp "to approximately 160 degrees Fahrenheit and maintaining the temperature at that point has proved most efiective and economical in producing the maximum recovery of lead, it is to he understood that the practice manger of the invention is not limited to this specific temperature, as temperatures ranging from 130 degrees Fahrenheit to somewhat below the boiling point of water have produced commensurately good recoveries.

What I claim is:

, 1. The method of preparing ores for flotation, which comprises treating the comminuted ore with a sulphidizing agent and water heated above v1.30 degrees Fahrenheit.

2. The method of preparing ores for flotation, which comprises treating'the comminuted ore with aqueous solution of a sulphidizing agent heated above 130 degrees Fahrenheit.

3. The method ofpreparing ores for flotation, which. comprises treating the comminuted ore with sodium sulphide and water heated above 130 degrees Fahrenheit. v

The method of preparing ores for flotation, which comprises agitating substantially equal weights of comminuted ore and water heated above 130 degrees Fahrenheit in the presence of a sulphidizing agent.

5. The method of preparing ores for flotation, which comprises agitating substantially equal weights of comminuted ore and water heated above l30degrees Fahrenheit in the presence of sodium sulphide.

6. The method of preparing ores for flotation, which comprises treating the ores with a sulphidizing hathheate'd above 130 degrees Fahrenheit. a

Z. The method of preparing ores for flotation, which comprises treating the comminuted ore with a sulphidizing agent and Water at a temperature of approximately 3.60 degrees Fahrenheit.

8. The method of preparing ores for flotation, which comprises treating the comminuted ore with sodium sulphide and water 1 at a temperature of'approximately 160 degrees Fahrenheit. I

9. iihe method of preparing ores for iotation, which comprises agitating substantially HARRY H. HENDRKCKSON. 

